Prime Minister Justin Trudeau's national security adviser says India is among the top sources of foreign interference in Canada.

Jody Thomas says "a number of state actors and non-state proxies" are conducting foreign interference in Canada, and at a conference last week she listed three countries that Ottawa has frequently cited: China, Russia and Iran.

But Thomas also specifically mentioned India, a country the Liberals highlighted in their Indo-Pacific strategy as a priority for establishing closer economic and scientific ties.

Federal agencies have in recent years warned that India may try to influence communities in Canada, and Thomas's predecessor suggested rogue elements in the Indian government sought to embarrass Trudeau during his visit that year.

On occasion India has argued that elements in Canada are behind interference in Indian domestic affairs, particularly a separatist movement led by some Sikhs that at times has involved violence.

The NDP has often cited India as a source of foreign interference, arguing Canada should limit its ties to the country over human rights concerns.